Impedance Cardiography

Project Overview

Project Statement: Impedance Cardiography is a medical procedure utilized in order to properly analyze and depict the flow of blood through the body. With this technique, four electrodes are attached to the body, two on the neck and two on the chest, which take beat by beat measurements blood volume and velocity changes in the aorta. However, this system withholds degrees of inaccuracy due to the mere fact that the electrodes are placed too far from the heart. Our collective goal is to design an accurate, reusable, spatially specific system that ensures more accurate and reliable readings.

The final constructed design prototype can be seen in the pictures below. It is made of a silicone rubber base upon which slits are cut on the ends, allowing an elastic strap to hold the system to the body. These slits are reinforced with a nylon plastic which decreases the chance of any ripping of the silicone to take place. Next, it is seen the base holds a matrix of modified electrodes. As seen in the picture below these modified electrodes consist of an extremely trimmed down base only including the electrode lead itself and the conductive foam on the bottom. It is also seen that in order to extend the electrode lead for easier hookup, a wire was wrapped around the lower part of the lead and then soldered to itself. The electrode was then threaded through the silicone base and the wire was tied in a knot in order to ensure a minimum movement in the electrodes. Lastly, looking on the underside of the prototype there is a hydrophobic mesh material. This is present in order to serve the purpose of prohibiting electrode gel to stray from one electrode to another. This would cause a short circuit and extremely distort the output signal.